ITB therapy offers significant relief from spasticity and is also used to treat pain…..
Spasticity is a motor disorder characterised by tight or stiff muscles that may hinder voluntary muscle activities.
It is generally seen in patients with spinal cord injuries (SCI), multiple sclerosis (MS), cerebral palsy (CP) and acquired brain injuries (ABI). Increased tone and spasm reduces the mobility and interferes with the activities of daily living, continence and sleep patterns.
Spasticity may be associated with significant pain or discomfort, skin breakdown, contractures and sleep disorders.
Spasticity is not always detrimental. It provides posture and tone to the limb that can assist with weight bearing, even if the patient cannot able to walk. However, excessive tone may interfere with activities.
Therefore, it is only when the spasticity interferes with the function or puts the patient at risk of hurting himself or herself that it needs to be treated.
The aim of the treatment is to reduce the spasticity in order to recover a range of motion, facilitate movements, decrease energy expenditure and reduces the risk of contractures.
Existing treatment comprises physical therapy, oral medications, injections of phenol or botulinum toxin and surgical intervention.
Baclofen is the most common oral drug, often prescribed for spasticity.
Baclofen is a
The proper patient selection, meticulous implantation technique, maintenance and the continued vigilance are of paramount importance to reduce the predictable iatrogenic complications and ensure maximum success.
The decision to implant baclofen pump requires careful evaluation of the multifaceted therapeutic measures to ensure the optimal treatment outcomes. When considering a pump, clinicians must consider the comorbidities related to disease and the psychosocial factors such as death and life expectancy.
Thorough explanation of what are the therapy entails and the need for continuous commitment for the therapy titration on part of the patient and the caretaker should be emphasized before proceeding for it.
Intrathecal pump is a device used for the chemical neuromodulation of central nervous system to significantly reduce the spasticity and pain.
It involves the implantation of a hardware to deliver the drug. It is a completely internalized drug delivery system comprising of an intrathecal catheter connected to a drug reservoir which is sited in the superficial subcutaneous pocket.
Administration of drug into the subarachnoid space, directly acts on the target receptors present on the dorsal horn cells which are responsible for pain transmission.
The intrathecal administration, allows the drug to bypass the enteric circulation/ absorption or the blood brain barrier hence the drug dose required for it , is a fraction of systemic dose with improved efficacy and hence minimized side-effects.
For example, the dose of baclofen from oral to intrathecal route decreases from approximately 300mg to 1mg. This continuous drug delivery system ensures a steady amount of drug level in blood, improving quality of analgesia. This is a modality which provides more effective pain relief.
There are a number of drugs which can be used with the system but the three drugs which are at present FDA approved are: Morphine, Baclofen and Ziconotide.
The Intrathecal drug pump system is a very sophisticated and programmable system.
It involves two stages. First is a trial phase, which is important to determine whether this particular system will suit the individual patient or not. It is just like test driving a car before buying it. Trial is performed to assess the patient’s response to the spasticity and improvement in side effects.
We perform trial by using intradural catheter (not bolus), which is implanted in strict aseptic conditions at the desired target site of the patient. The patient is then assessed for the improvement in spasticity of the target areas after 2, 4 and 6 hours.
We usually observe the patient in ICU during this time for better patient safety. If the trial is successful, we proceed for the implantation. After implantation the system is programmed accordingly to offer long lasting benefit in terms of satisfactory control of pain and spasticity.
The implantation of baclofen pump is performed in OT using fluoroscopic guidance and all surgical asepsis precautions.
The two pieces of silicone catheter is introduced through a special introducer needle and guided into the subarachnoid space up to the desired level depending upon the pain geography and properties of the drug used. It is then secured to the thoracolumbar fascia with special anchor, tunnelled in the subcutaneous plane and connected to the Synchro-med pump by suture less connector on the proximal piece of the catheter.
The pump is then emptied of its manufacturing fluid and filled with the desired drug to be administered before implanting in the subcutaneous pocket. Both the incisions are then surgically sutured after adequate haemostasis.
The Intrathecal pump is available in two main types, fixed rate [Isomed] and programmable [Synchromed] pump. The Synchromed pump has two varieties, an older Synchromed El and a newer Synchromed II system.
The Synchromed II has been an improved version and has been more popular due to its features such as lighter and flatter implant, increased drug stability upto 6 months and improved low reservoir flow accuracy.
It comes in two different sizes, 20ml and 40ml reservoir capacity. Improved software of Synchromed II stores all the patients demographics and notes up to 1000 characters. It can also stores catheter information and system log with last 30 events and the patient activation log of last 80 events.
This information is more useful when technical support is required for help. The information is presented in a scrollable window to accommodate more information with the multiple drugs. New software also allows drug data up to 5 drugs with the first drug as a primary drug.
A personal therapy manager (PTM) is a compact device which enable the patient to take extra boluses if required for the incidental or breakthrough pain. This gives a better degree of patient satisfaction.
The main drawback of using this beclofen system especially in our country is the cost. There should be reasonable life expectancy [at least three months] before taking consideration of implanting this device.
Valuations of its cost-effectiveness recommend that cost savings are achieved after 2 years in contrast to systemic pharmacologic therapy for chronic and non-cancer pains.
Complications related to the intrathecal therapy can be technical, biological, and medication related.
While the huge majority of the difficulties are minor, some serious problems can also occur including Granuloma formation that may be related to the amount and concentration of the opiates, mostly with high concentrations of Morphine and Hydromorphine.
Surgical intervention required is rare as most of the cases improve with weaning off the intrathecal opiate, replacing it with the preservative-free saline which has been shown to reverse the course leading to resolution of the Granulomas.
Granuloma may also occur in as many as 3% of the implanted patients and most are asymptomatic. Routine MRIs to rule out the intrathecal Granuloma were not recommended by the authors of this prospective study, given the relatively low incidence.
The initial sign of Granuloma may be the increased pain despite of increasing the opiate infusion; hence, clinical vigilance is of prime importance.
Other difficulties of IDDS include catheter migration, catheter kinking, catheter fracture/ leakage, CSF leak, Seroma formation, Hygroma, Infection, Pump erosion through the skin and medication side effects as pruritus, vomiting, nausea, respiratory depression and cognitive side effects may occur.
It is important to realize that clinician skills and expertise is vital as programming errors can be dangerous to the patient.
A follow up at regular intervals [average every three months] is essential for refill of the drug in the pump reservoir and titration of the dose of drug to achieve the best possible analgesia is required. The battery of the pump requires surgical replacement about every 5-7 years depending upon the flow rate used.
